Automotive fuel injection system

Abstract

An automotive fuel injection system for detecting as quickly as possible the occurrence of acceleration without employing a throttle sensor to thereby perform an asynchronous fuel injection for the purpose of maintaining the air-to-fuel ratio of the combustible air-fuel mixture at an optimum value during the acceleration of the automotive engine. The automotive fuel injection system comprises a device for comparing the pressure inside the fuel intake system with an average value of the pressures inside the fuel intake system. When the pressure prevailing in the fuel intake system deviates by a predetermined quantity from the average pressure inside the fuel intake system, acceleration is deemed as actually occurring in the automotive engine and, hence, asynchronous fuel injection is effected substantially simultaneously with the detection of the occurrence of engine acceleration.

What is claimed is: 
     
       1. A fuel injection system for use in association with an automotive combustion engine designed to effect an injection of fuel into a combustion engine in synchronism with a signal generated each time a predetermined cranking angle is attained or at each ignition timing by calculating the amount of fuel to be injected through detection of a pressure inside a fuel intake system of the combustion engine, said system comprising: a pressure detecting means for detecting the pressure inside the fuel intake system of the combustion engine; and   a control means operable to calculate an average pressure value by averaging output signals generated by the pressure detecting means and also to determine that the combustion engine is being accelerated in the event that the output signal generated by the pressure detecting means deviates from the average pressure value by a quantity equal to or greater than a predetermined value, thereby to effect an asynchronous fuel injection in the event that the combustion engine is deemed to have accelerated.   
     
     
       2. A fuel injection system for use in an automotive power plant including a combustion engine having at least one combustion chamber, which comprises: a fuel injector means for injecting fuel into the combustion chamber at a predetermined timing synchronized with an ignition timing;   a pressure sensor for detecting a pressure inside a fuel intake passage communicating with the combustion chamber and providing a pressure signal; and   a control system including an averaging means adapted to receive the pressure signal from the pressure sensor for calculating an average pressure of the pressure signals supplied from the pressure sensor during cycles of operation of the combustion engine, a detecting means for comparing the pressure signal, supplied from the pressure sensor during a certain cycle of operation of the combustion engine, with the average pressure calculated by said averaging means, and a pulse generating means for generating a drive pulse for driving the fuel injector means to effect an injection of fuel into the combustion chamber in the event that the pressure signal supplied by the pressure sensor during said certain cycle of operation of the combustion engine deviates from the average pressure by a quantity equal to or higher than a predetermined amount, signifying an occurrence of acceleration of the combustion engine.